JPH08208827A - Production of thermoplastic polycarbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the title carbonate, solvent-free and light in color, that is capable of completing the reaction quickly and is useful in the field of electrical engineering or the like by reacting an aromatic diphenol and a carbonic acid diaryl ester in gas phase.

SOLUTION: The carbonate having an average molecular weight of, preferably, 300-24,000 is obtained by combining and reacting (A) an aromatic diphenol (preferably, a bisphenol A) and (B) a carbonic acid diaryl ester (preferably, a diphenyl carbonate) in gaseous form (preferably, under an absolute pressure of 1,000 to 0.01 mb and at a temperature of 80-400°C). It is preferable that the gas-phase reaction is carried out in the presence of a basic or neutral catalyst, for example, an ammonium and a phosphonium catalyst of the formula (wherein each R₁ to R₄ are independently alkyl, aryl or cycloalkyl; and X^- is an anion in which the corresponding acid/base pair H⁺+X^-←→HX has a pKB<11) or the like, and a guanidine and a phosphazene base or the like.

COPYRIGHT: (C)1996,JPO

Description

Detailed Description of the Invention

The invention relates to aromatic diphenols, carbonic acid diaryl esters, optionally branching agents and / or monophenols and optionally catalysts, at temperatures of from 80 to 400 ° C. and at 100 ° C.
Oligo / at absolute pressures of 0-0.01 mbar
The present invention relates to a method for producing an oligo / polycarbonate, which comprises reacting an aromatic diphenol and a carbonic acid diaryl ester in a vapor phase in the first step of transesterification (oligocarbonate production step) when producing a polycarbonate by a solventless transesterification method.

The oligo / polycarbonates produced by the process of the present invention are solvent-free, light in color, and substantially free of the undesirable disadvantages of polycarbonate.

Aromatic oligo / by melt transesterification method
The production of polycarbonates is known from the literature, for example H.S. Schnell, Chemistry and Physics of Polycarbonate, Polymer Reviews,
Volume 9, John Wiley & Sons (John Wil
ey & Sons. Inc.) (1964).

In the references and references cited therein, solid educts (aromatic diphenols, carbonic acid diaryl esters) are always melted and reacted to produce polycarbonate.

Surprisingly this time, by combining an aromatic diphenol in the gas phase with a carbonic acid diaryl ester,
It has been discovered that the reaction can be completed rapidly. This has the special advantage that the educts can be used in very high amounts immediately after purification by distillation without the need for further steps. Isolation and subsequent remelting is unnecessary.

Suitable diphenols for the process of the present invention have the formula (I)

[0007]

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[Wherein X = C _1-8 alkylidene or cycloalkylidene, S or a single bond, R = CH ₃ , Cl or Br, and n = 0, 1 or 2].

Suitable diphenols are, for example, 4,4'-
Dihydroxydiphenyl, 4,4'-dihydroxydiphenyl sulfide, 2,2-bis- (4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dimethyl-4-hydroxyphenyl) ) -Propane, 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) -propane, 1, 1-bis- (4-hydroxyphenyl) -cyclohexane and 1,1-bis-
(4-hydroxyphenyl) -3,3,5-trimethylcyclohexane. Of the diphenols mentioned above,
2,2-bis- (4-hydroxyphenyl) -propane and 1,1-bis- (4-hydroxyphenyl) -3,
3,5-Trimethylcyclohexane is particularly preferred.

The diphenols mentioned above can be used for the production of homopolymers or copolymers. Polycarbonates may be deliberately and controllably branched by using small amounts of branched chains. Suitable branching agents are chloroglucinol, 4,6-dimethyl-2,4,6-tri-.
(4-hydroxyphenyl) -hept-2-ene, 4,
6-Dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzene, 1,1,1-tri- (4 -Hydroxyphenyl) -ethane, tri- (4-hydroxyphenyl) -phenylmethane, 2,2-bis- [4,4-bis- (4-hydroxyphenyl) -cyclohexyl] -propane, 2,4- Bis- (4-hydroxyphenylisopropyl) -phenol, 2,6-bis- (2-hydroxy-5'-methylbenzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2 , 4-
Dihydroxyphenyl) -propane, hexa- (4-
(4-Hydroxyphenylisopropyl) -phenol) -orthoterephthalic acid ester, tetra- (4-hydroxyphenyl) -methane, tetra- (4- (4-hydroxyphenylisopropyl) -phenoxy) -methane, 1, 4-bis- (4 ', 4 "-dihydroxytriphenyl) -methyl) -benzene and more particularly α, α', α"
-Tris- (4-hydroxyphenyl) -1,3,5-triisopropylbenzene.

Other possible branching agents are 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and 3,3-bis- (3-methyl-4-hydroxyphenyl) -2-oxo-2. It is 3,3-dihydroindole.

The optionally used branching agent is used with diphenols in an amount of 0.05 to 2 mol% based on the diphenol used, or may preferably be added late in the oligo / polycondensation.

Carbonic acid diesters in the context of the present invention include di-C _6-18 aryl esters, halogen-substituted NO ₂
Substituted carbonic acid diesters, preferably diesters of phenols or alkyl-substituted phenols, ie diphenyl carbonates or, for example, dicresyl carbonate. The carbonic acid diester is 1.01 to 2 moles, preferably 1. 1 moles per mole of bisphenol.
02 to 1.30 mol, more preferably 1.03 to 1.15
Used in molar amounts.

In the process of the present invention, the aromatic dihydroxy compound and the carbonic acid diester may be evaporated for a gas phase reaction or, preferably, combined in the gas phase after the purification step (distillation).

The gas-phase reaction of oligocarbonates takes place in the absence of catalysts. However, nitrogen and phosphorus bases, such as ammonium and phosphonium catalysts (Ref. I
II, IV) and guanidine and phosphazene bases can advantageously be used as catalysts for gas phase reactions leading to oligocarbonates. These catalysts may be used in the gas phase or fixed on a carrier as a fixed bed catalyst.

Suitable catalysts for the preparation of oligocarbonates suitable for use in the process of the invention are those of the general formulas (III) and (IV)

[0017]

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Wherein R _1-4 may be the same or different and represent an alkyl, aryl or cycloalkyl group, and X ⁻ may be an anion and the corresponding acid /
Bp H ^{+ +} X ^- ⇔HX are compounds corresponding to] having a pK _B <11.

Examples of catalysts suitable for use in the method of the present invention are ammonia, tetramethylammonium hydroxide, tetramethylammonium acetate, tetramethylammonium fluoride, tetramethylammonium tetraphenylboranate, tetraphenylphosphonium. Fluoride, tetraphenylphosphonium tetraphenylboranate, dimethyldiphenylammonium hydroxide, tetraethylammonium hydroxy, DB
U, DBN or guanidine series, such as 1,5,7-triazabicyclo- [4,4,0] -dec-5-ene, 7-phenyl-1,5,7-triazabicyclo- [4,4 , 0] - dec-5-ene, 7-methyl-1,5,7-triazabicyclo - [4,4,0] - dec-5-ene, 7,7 ¹ - hexylidene - di-1,5 , 7-Triazabicyclo- [4,4,0]
- dec-5-ene, 7,7 ¹ - decylidene - di -1,5,7
-Triazabicyclo- [4,4,0] -dec-5-ene,
7,7 ¹ - dodecylidene - di-1,5,7-triazabicyclo - [4,4,0] - dec-5-ene, or Hosufuazen, e.g. Hosufuazen base P _1-t-oct = ter
t-octyl-iminotris- (dimethylamino) -phosphorane, phosphazene base P ₁ t-butyl = tert
-Butyliminotris- (dimethylamino) -phosphorane, BEMP = 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3-diaza-2-phosphorine.

These catalysts are used in an amount of 10 per mol of phenol.
Used in an amount of ^-1 to 10 ^-8 mol. The catalysts (2 or 3) may be used in combination with each other.

Support materials for fixed bed catalysts and the above mentioned catalysts are glass, zeolite, aluminum oxide, activated carbon, metals / alloys, ceramics and polymer supports.

For catalystless reactions, it is advantageous to form a large surface area due to the gas phase reaction. This includes glass, zeolites, activated carbon, inert metals / alloys (eg V4A, Hastelloy) that provide a large surface area with corresponding geometrical shapes (eg spheres, nets, powders, rings, granules, pellets). This can be ensured by passing the gas mixture over the material.

The oligocarbonates formed in the gas phase reaction are determined by measuring the relative solution viscosities in dichloromethane or an equal weight mixture of phenol and o-dichlorobenzene and calibrating by light scattering. 300-2
It has an average molecular weight Mw of 4,000, preferably 400 to 19,000.

The temperature for producing the oligocarbonate is in the range of 100 to 350 ° C, preferably 150 to 280 ° C. The monophenols formed during the transesterification to oligocarbonates are removed by applying an absolute pressure of 1 bar to 0.5 mbar, preferably <500 to 7 mbar. However, a low partial pressure may be established by using a corresponding amount of carrier gas (inert gas such as nitrogen, argon, carbon dioxide, steam).

In the process of the invention, the production of oligocarbonates by reaction of aromatic dihydroxy compounds and carbonic acid diesters can be carried out discontinuously or preferably continuously. For this purpose, the gasses of aromatic dihydroxy compounds and carbonic acid diesters are expanded to suitable technical means (eg nozzles, mixing elements, suitable geometrical shapes (eg spheres, nets, powders, rings, granules, pellets)). Glass, zeolite, activated carbon, which provides mixed surface area,
Mixing and reacting by using a flow over material such as an inert metal / alloy). The reaction can be carried out, for example, in a simple heating tube or in a packed reaction column (packing: glass in suitable form (eg spheres, nets, powders, rings, granules, pellets), zeolite, activated carbon, inert metals / alloys, (Ceramics, supported catalyst).

The residence time of the aromatic dihydroxy compound and the carbonic acid diester in the gas phase reaction leading to the oligocarbonate of the method of the present invention is much shorter than that in the liquid phase reaction (1 to 5 hours), preferably 1 hour or less, preferably It is 0.5 hours or less, more preferably 15 minutes or less.

The oligocarbonate is then added to, for example, a stirred tank reactor, a thin layer evaporator, a reaction column, a loop reactor, a tube coil containing flash evaporation, a descending film evaporator, a cascade stirred tank reactor, a simple disk reaction. It is further reacted by introducing it into the vessel.

Oligocarbonates are <100-0.0
It is converted to polycarbonate by further raising the temperature to 250-400 ° C., preferably 280-320 ° C. under 1 mbar.

It is advantageous to add an alkali metal / alkaline earth metal catalyst to this stage. The alkali metal / alkaline earth metal catalyst is preferably diphenol 1
10 ^-8 to 10 ^-4 mol, and more preferably 10 ^-7 to 10 mol per mol.
Used at a concentration of 10 ^-3 molar. Examples of corresponding catalysts are
Lithium, sodium, potassium, cesium, calcium, barium, magnesium hydroxides, carbonates, halides, phenolates, diphenolates, fluorides, acetates, phosphates, hydrogen phosphates and boranes.

The alkali metal / alkaline earth metal catalyst is
It can be added, for example, as a solid or as a solution in water, phenol, oligocarbonate, polycarbonate or as a master batch.

In the process according to the invention, the polycondensation of oligocarbonates can be continuous or discontinuous, for example stirred tank reactors, thin layer evaporators, cascaded stirred tank reactors, extruders, kneaders, disk reactions. Can be carried out in a vessel and / or in a high viscosity disk reactor.

Aromatic polycarbonates according to the method of the invention are measured for relative solution viscosity in dichloromethane or in an equal weight mixture of phenol and o-dichlorobenzene,
Determined by calibrating with the light scattering method,
0-60,000, preferably 19,000-40,000
It should have a weight average molecular weight of zero.

This involves the polycondensation of low molecular weight oligocarbonates to relatively low viscosity polycarbonates and relatively high molecular weight oligocarbonates to relatively high viscosity polycarbonates, preferably by distilling off the monophenols. It will be done. The production of polycarbonates by the reaction of oligocarbonates is described in WO 90/753.
No. 6 or European Patent No. 338085, the oligocarbonate produced by the method of the present invention may be crystallized and subjected to polycondensation in a solid phase.

The aromatic polycarbonates of the process of the invention are determined by measuring the relative solution viscosities in dichloromethane or an equal weight mixture of phenol and o-dichlorobenzene and calibrating by light scattering. 18,000
To 60,000, preferably 19,000 to 40,000
Should have a weight average molecular weight of.

The polycarbonate produced according to the invention is bright in color and preferably has a low terminal OH of <1200 ppm.
It has a group content and is resistant to hydrolysis and heat.

To limit the weight average molecular weight of the polymer,
A molecular weight regulator such as an alkylphenol (isooctylphenol, t-butylphenol, cumylphenol) can be used in a required amount according to a known method (Europepa Patent No. 360,578).

Auxiliary agents and reinforcing agents may be added to the polycarbonate produced according to the present invention to improve its properties. Suitable auxiliaries and toughening agents include stabilizers (eg UV,
Heat, γ-ray stabilizer), antistatic agent, flow aid, release agent,
Flame retardants, pigments, particulate minerals, fibers such as alkyl and aryl phosphites, phosphates and phosphanes,
Includes low molecular weight carboxylic acid esters, halogen compounds, salts, chioke, silica powder, glass and carbon fibers, acids and epoxides.

Other polymers such as polyolefins, polyurethanes, polystyrenes may also be mixed with the polycarbonates of this invention.

These materials are preferably added to the final polycarbonate in conventional equipment, although they can be added at other stages of the process of the invention if desired.

In addition, the polycarbonates may be used for special applications in blocks, segments and comonomers such as OH terminated siloxane blocks, aromatic and aliphatic OH and carboxylic acid terminated polyesters, OH terminated polyphenylene sulfides. The block may be modified by co-condensation of an OH-terminated polyphenylene oxide block.

The polycarbonate produced according to the present invention is
In the usual applications, namely electrical engineering, the construction sector and the automotive industry, for example as support material for data storage media, coatings as the intended double-wall panel or as housing material for electronic devices.

[0042]

Example 1 1 kg of bisphenol A and 1 kg of diphenyl carbonate were separately weighed into two oil-heated vessels and melted under nitrogen. The oil-heated container was provided with two heating connecting pipes opening into a heated glass tube (glass ring filling). This glass tube (length 30 cm and diameter 7.5c
m) ended with a 2 l 2-necked flask (heated) equipped with a product outlet and fitted with a bridge. Heat bisphenol A to 290 ° C and diphenyl carbonate at 250 ° C.
Heated up. The heated glass tube was heated to 230 ° C, and the 2 liter two-necked flask was heated to 210 ° C. The pressure was then continuously reduced to 40 mbar so that the bisphenol A and diphenyl carbonate boil uniformly. Uniform boiling could be adjusted by readjusting the separation temperature. Then, the synthesis of oligocarbonate proceeded in a heated glass tube, and the oligocarbonate was separated in a 2-liter two-necked flask. The desorbed phenol was continuously removed through the bridge. The oligocarbonate with a relative solution viscosity of 1.038 (dichloromethane, 25 ° C., 5 g / l) is discharged into a flask equipped with a stirrer, an internal thermometer and a Vigreux column (30 cm, reflexive) and at the same time the temperature is maintained for 1 hour. The temperature was increased to 250 ° C. and the vacuum reduced to 10 mbar. The polycondensation was completed over 1 hour by further reducing the vacuum to 0.5 mbar and raising the temperature to 250 ° C. Relative solution viscosity 1.230 (dichloromethane, 25 ° C, 5g / l)
A light-colored polycarbonate was obtained without solvent. The polycarbonate had a phenolic OH value of 510 ppm.

Example 2 As in Example 1, except that a V4a quartz ring was used in place of the glass ring. The obtained oligocarbonate had a relative solution viscosity of 1.045 (dichloromethane, 25 ° C., 5
g / l) and a light-coloured solvent-free polycarbonate having a relative solution viscosity of 1.254 (dichloromethane, 25 ° C., 5 g / l).

Example 3 As in the example, but with 0.0001 g of NaOH (5 × 10 ^-4 mol%, based on bisphenol A) being added to the oligocarbonate in the form of a 1% aqueous solution. A light-coloured, solvent-free polycarbonate having a relative solution viscosity of 1.299 (dichloromethane, 25 ° C., 5 g / l) was obtained. This polycarbonate had a phenolic OH value of 280 ppm.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Thomas Fuchsia Germany 47809 Kleefert Emile-Fuinendengen-Schuttraße 2 (72) Inventor Gottfried Zurbi Germany 51375 Lehuelkusen Berghi Sierland Schutlerse 124 Be ( 72) Inventor Franz-Fuerdendant Reel Germany $ 41,540 Magen Phuauensis Utraße 26

Claims (7)

[Claims] 1. A process for the preparation of thermoplastic, solvent-free oligo / polycarbonates in which an aromatic diphenol and a carbonic acid diaryl ester are combined and reacted in the gaseous form. 2. The process according to claim 1, which is carried out at a temperature of 80 to 400 ° C. under an absolute pressure of 1000 to 0.01 mbar. 3. The method of claims 1 and 2 wherein the diphenol is bisphenol A and the carbonic acid diaryl ester is diphenyl carbonate. 4. The method according to claims 1 to 3, wherein the gas phase reaction is carried out in the presence of a basic or neutral catalyst. 5. The process according to claims 1 to 4, wherein the oligocarbonate produced in the gas phase reaction has an average molecular weight Mw of 300 to 24000. 6. The process of claims 1-5, wherein the residence time for oligocarbonate synthesis is 2 hours or less. 7. The method of claim 4 wherein the catalyst is a fixed bed catalyst.